Cristiano Ronaldo showed he was equal to the biggest of occasions with a superb header for Real Madrid against former club Manchester United as their Champions League last-16 first-leg showdown ended 1-1 on Wednesday.

Watched by millions around the world, the hotly-anticipated clash at the Bernabeu was Portuguese Ronaldo’s first game against the club where he made his name before joining Real for a world-record fee in 2009.

It also renewed the rivalry between Real coach Jose Mourinho and his United counterpart Alex Ferguson as the La Liga champions seek the 10th European title that has eluded them since 2002 and the Premier League leaders chase a fourth triumph in Europe’s elite club competition.

United withstood an early Real onslaught and drew first blood against the run of play in the 20th minute when Danny Welbeck nodded past Diego Lopez from a Wayne Rooney corner. Ronaldo levelled 10 minutes later when he towered above Patrice Evra to send an Angel Di Maria centre arrowing into the corner.

The result gave United a slight advantage for the return leg in Manchester on March 5, although both sides will regret squandering chances in the second half that could have eased their passage to the last eight.

Ronaldo, top scorer in this season's Champions League with seven goals in seven appearances, barely celebrated his goal and spoke of the debt he owes United, where he was transformed from an inexperienced and fragile teenager into one of the world’s most formidable forwards.

Real attacked the visitors’ goal from the start, United goalkeeper David De Gea tipping a Fabio Coentrao effort on to a post in the sixth minute as a ragged United struggled to retain possession.

They had yet to have an attempt on goal when Welbeck spun away from Sergio Ramos and nodded inside the post for only his second goal in 28 matches. Ronaldo, given a rousing ovation from both sets of fans before kickoff, went close following up on his own free-kick before his equaliser sent the home fans into raptures.

Real were far more threatening going forward but nearly conceded a second in the 34th minute when Welbeck came close to poking a Robin van Persie centre past Diego Lopez.

United started the second half brightly but were soon on the back foot again as Real surged forward in search of a second.

De Gea, who joined United from Real's city rivals Atletico Madrid, again denied Coentrao on the hour when he flung himself to hook the fullback's goal-bound shot away with his right boot. Although they were seeing little of the ball, United managed to create a number of dangerous openings.

Lopez tipped a searing Van Persie drive on to the bar in the 72nd minute moments before the Netherlands striker squandered a golden chance for United's second.

Dortmund grab draw

Borussia Dortmund grabbed a late 2-2 draw at Shakhtar Donetsk in the night’s other last-16 first-leg tie which was overshadowed by a fatal plane crash involving fans. Mats Hummels headed in an 87th-minute corner after substitute Douglas Costa thought he had won it for the hosts in the 68th minute to leave the Germans as favourites ahead of the second leg in Dortmund on March 5.

Darijo Srna put Shakhtar ahead with a 31st-minute free-kick but Dortmund deservedly scored through Robert Lewandowski four minutes before the break.

The match went ahead despite at least five people being killed when a plane carrying supporters to the match in eastern Ukraine overshot the Donetsk runway and broke up as it attempted an emergency landing in the fog hours before kickoff.

Dortmund dominated early on with several half chances but Felipe Santana then committed a needless foul and Srna's dipping effort went in past goalkeeper Roman Weidenfeller who could have done better.

The visitors, who also hit the bar through Hummels, levelled when Poland's Lewandowski completely miskicked in the box but the ball fell kindly for the striker and he coolly slotted home.